package model;


import com.mysql.jdbc.jdbc2.optional.MysqlDataSource;
import javax.sql.DataSource;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

public class DBUtil {
    private static  volatile DataSource dataSource = null;//单例实现,懒汉模式

    private static DataSource getDataSource() {
        if (dataSource == null){
            synchronized (DBUtil.class){ //针对类对象进行加锁，保证线程安全
                if (dataSource == null){ //双层锁
                    dataSource = new MysqlDataSource();
                    ((MysqlDataSource)dataSource).setUrl("jdbc:mysql://127.0.0.1:3306/blog_system?characterEncoding=utf8&useSSL=false");
                    ((MysqlDataSource)dataSource).setUser("root");
                    ((MysqlDataSource)dataSource).setPassword("");
                }
            }
        }

        return dataSource;
    }

    public static Connection getConnection() throws SQLException {
        return getDataSource().getConnection();
    }

    public static void close(Connection connection, PreparedStatement statement, ResultSet resultSet) {
        if (resultSet != null){
            try{
                resultSet.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }

        if (statement != null){
            try{
                statement.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }

        if (connection != null){
            try{
                connection.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }


    }
}


